Technical Field
The present disclosure relates to an antenna device compatible with multiple bands, which is configured by connecting a high-band antenna element and a low-band antenna element at one feed point, and a communication apparatus including the antenna device.
There is a method in which an antenna element length is shortened with an inductor as an existing technique of providing a wideband antenna. For example, Patent Document 1 discloses that a resonant frequency of an antenna is varied by connecting a tapped inductor to an antenna element, enabling a tap to be selected by a switch, and switching a shortening rate of the antenna element with the selection of the tap.
There is a method in which electric power is fed to an antenna compatible with a plurality of bands using a common feed point as one technique of making the antenna operable in multiple bands. For example, Patent Document 2 discloses a dual band antenna having a single feed point and having a what-is-called bifurcate structure, which is operable in two bands. In the antenna device disclosed in Patent Document 2, an impedance matching portion is inserted and connected between an end portion of an antenna element for a high-frequency band at the feed point side and an open end portion thereof.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2001-344574
Patent Document 2: Japanese Unexamined Patent Application Publication No. 2010-10960